“Research recommends having no more than 400 milligrams of caffeine a day,” says nutritionist Amy Gorin, owner of Amy Gorin Nutrition in Jersey City, New Jersey. Increasing your intake to more than the recommended amount may result in health complications — increased blood pressure, anxiety and increased risk for osteoporosis, to name a few.
Caffeine is a stimulant because it has the ability to speed up your central nervous system and increase your heartbeat. When your heart is beating too fast, you may begin to feel dizzy and, in some cases, you may even experience fainting spells. You may also feel more alert and experience the “jitters,” and feel irritable because of all this as well.
Withdrawal symptoms are also common among frequent coffee-drinkers. Without the caffeine, some people experience loss of concentration, headaches, and drowsiness.